There is a wide difference between a bond secured by one or more real estate first mortgages, and an unsecured debenture bond. The former has definite real property pledged to secure it in addition to the bondsman's obligation, the latter is an agreement to repay the principal and interest, but with no property specifically pledged as security. In fact, the property of a corporation issuing debenture bonds is usually encumbered by one or more mortgages, so that the company owns merely equities. The property may be lost through foreclosure or its value may decrease. Should the company fail, the debenture bond holders become general creditors. No debenture bond should be purchased except after careful inquiry into the affairs of the company and an appraisal of the real estate equities and other assets it owns.